<!DOCTYPE html>
<html>
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
	<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
	<style type="text/css">
		body, html,#allmap {width: 100%;height: 100%;overflow: hidden;margin:0;font-family:"微软雅黑";}
	</style>
	<script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=您的密钥"></script>
	<title>获取地图显示范围</title>
</head>
<body>
	<div id="allmap"></div>
</body>
</html>
<script type="text/javascript">
	// 百度地图API功能
	var map = new BMap.Map("allmap");            
	map.centerAndZoom(new BMap.Point(116.4035,39.915), 14);  
	var bs = map.getBounds();   //获取可视区域
	var bssw = bs.getSouthWest();   //可视区域左下角
	var bsne = bs.getNorthEast();   //可视区域右上角
	alert("当前地图可视范围是：" + bssw.lng + "," + bssw.lat + "到" + bsne.lng + "," + bsne.lat);
</script>
